The tub assembly can move on its suspension; that is not the same as the inner drum having play relative to it. A drum that is permanently off-center, rubbing, or sagging requires the appliance to be taken out of service.
Check which part is moving
Unplug the appliance before carrying out any accessible inspection. In a horizontal-axis drum, it is important to distinguish movement of the entire suspended assembly from the relative movement of the inner drum. Do not lift forcefully or look for a universal tolerance: the behavior depends on the design.
Note whether the gap around the opening is uneven, whether there are marks on the seal, or whether a slight movement causes contact. Avoid running a spin cycle to document a knock that is already obvious.
What service should check
The suspension supports and controls the tub assembly. The bearings and the support or shaft are involved in supporting the inner drum. Identifying which mechanical relationship has changed makes it possible to inspect the correct assembly.
Wear or damage can affect more than one area. If a rubbing seal is replaced without correcting the misalignment, the contact can return. A door leak accompanied by rubbing should be described together with the looseness.
Useful information for assessing the repair
Provide the model, when it started, whether there was increasing noise or a sudden knock, and whether there were any previous leaks. The technician should confirm the damage and the availability of the corresponding assembly before providing an estimate.
Leveling the feet does not correct a drum that shifts relative to its own internal supports.